Social networking system capable of providing location-based notifications

ABSTRACT

A networked computer system provides various services for assisting users in locating, and establishing contact relationships with, other users. For example, in one embodiment, users can identify other users based on their affiliations with particular schools or other organizations. The system also provides a mechanism for a user to selectively establish contact relationships or connections with other users, and to grant permissions for such other users to view personal information of the user. The system may also include features for enabling users to identify contacts of their respective contacts. In addition, the system may automatically notify users of personal information updates made by their respective contacts.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 12/506,167, filed Jul. 20, 2009, which is a division of U.S. application Ser. No. 12/127,495, filed May 27, 2008 (now U.S. Pat. No. 7,739,139), which is a continuation of U.S. application Ser. No. 11/022,089, filed Dec. 22, 2004 (now U.S. Pat. No. 7,386,464), which is a division of U.S. patent application Ser. No. 10/780,486, filed Feb. 17, 2004 (now U.S. Pat. No. 7,194,419), which is a continuation of U.S. patent application Ser. No. 09/348,355, filed Jul. 7, 1999 (now U.S. Pat. No. 6,714,916), which is a continuation of U.S. application Ser. No. 08/962,997, filed Nov. 2, 1997 (now U.S. Pat. No. 6,269,369).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to multi-user computer systems, such as contact management systems, that provide services for users to locate and share personal information with other users.

2. Description of Related Art

Several types of prior art for managing contact information exist, including Personal Information Management software applications, Groupware Applications, and Internet-based “White Pages” and e-mail services.

Personal Information Management Software.

As represented generally in FIG. 1, in a typical prior art Personal Information Management (PIM) software application (e.g., Lotus Organizer, Microsoft Outlook, or U.S. Robotics Palm Pilot), a PIM software application 120, 124 that stores contact information in a database resides on a workstation or handheld computer 100 having a central processing unit 102, a display 108, a keyboard and/or mouse 110, a primary memory 104 (e.g., random access memory) for program execution, a secondary memory 106 (e.g., a hard disc) for program storage, and peripheral devices 112. As is well known, programs, such as the PIM software 120, are executed in the RAM 104 by the CPU 102 under control of the operating system software 122, 126.

In the prior art, users themselves enter the contact information that they want to store in the PIM software. A variety of methods exist for entering this contact information. It may be entered manually using the keyboard, imported from an existing file on their computer, or imported via a peripheral device such as a business card scanner. The defining characteristic of this class of prior art is that the input of the contact information is performed by the user of the software and, when the information changes, the user must modify the information himself. What this class of prior art lacks is a means for information to be shared between multiple users and a means for a given user to post changes to his own information for the benefit of others.

Groupware Applications.

As generally represented in FIG. 2, in a typical prior art Groupware application (e.g., Lotus Notes), a user workstation 160 accesses information stored on a central server computer 130 over a computer network 150, such as a Local Area Network or Intranet. The server system consists of a central processing unit 132, a primary memory 134 (e.g., random access memory) for program execution, a secondary storage device 136 (e.g., a hard disc) for program storage, and a modem 138 or other device for connecting to the computer network. The user workstation 160 is the same as the user workstation 100 described in reference to FIG. 1 with the addition of a modem 162 or other device for connecting to the computer network. The file server or database contains data files 148 that can be accessed only by authorized users. The user uses client software 174, 176 running on the user workstation 160 to access the files 148 under the mediation of server software 140, 144 running on the server 130.

Typically, in such a system a central system administrator organizes users into classes and the creator of a file 148 determines what classes of users may view the file. The rules governing which individual users or classes of users have the authorization to view a particular file 148 may be stored as part of the file itself. Alternatively, these rules are based upon the hierarchical directory structure of the file server in which the file is stored. That is, a particular user may view files in one directory but not another.

FIG. 3 represents a common deployment of a contact management system based on Groupware. Each user enters information 202 about himself and specifies a set of permissions 204 that define what classes of users are able to view various pieces of the information 202. What this deployment of the prior art lacks is the ability to authorize viewing privileges on a user-by-user basis rather than on a class-by-class basis. For instance, a user would be able to grant access to his home phone number 206 to the Human Resources department of his employer (e.g., Class A) while denying access to the same information to his co-workers (e.g., Class C). The user would not be able to give access to his home phone number selectively to a first co-worker while denying it to a second co-worker if both co-workers were part of the same class of users as organized by the central system administrator. Furthermore, such a system would lack a practical notification methodology. There would be no way for a user to specify “notify me when the first co-worker changes his information but not when the second co-worker changes his information.”

Internet-Based “White Pages” and E-Mail Directory Services.

In a typical prior art “white pages” or e-mail service, client computers and a server computer are connected via the World Wide Web as depicted in FIG. 4. A user subscribes to a White Pages or E-Mail service via a client computer 270 operating a web browser 282 or other software application residing in memory 274 that allows it to display information downloaded from a server computer 230 over the World Wide Web 260. The server computer system accesses a database 240 containing contact information entered by registered users. The service enables users to view contact information entered by other users. The authorization scheme may allow all users to limit certain classes of users from viewing certain parts of their user record as represented in FIG. 3. However, there are no linkages between individual users and thus users cannot restrict the viewing of their information on a user-by-user basis. Furthermore, users cannot be notified when information for particular users has changed.

SUMMARY

A networked computer system provides various services for assisting users in locating, and establishing contact relationships with, other users. For example, in one embodiment, users can identify other users based on their affiliations with particular schools or other organizations. The system also provides a mechanism for a user to selectively establish contact relationships or connections with other users, and to grant permissions for such other users to view personal information of the user. The system may also include features for enabling users to identify contacts of their respective contacts. In addition, the system may automatically notify users of personal information updates made by their respective contacts.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention, wherein:

FIG. 1 depicts a computer loaded with Personal Information Management software;

FIG. 2 generally depicts the data schema of a category of prior art known as groupware applications;

FIG. 3 shows a common scheme for authorizing permission to view information in the prior art;

FIG. 4 depicts two computers interconnected via the Internet, one of which is a server connected to a database and the other of which represents a user's client workstation, both of which are configured according to the prior art;

FIG. 5 depicts two computers interconnected via the Internet, one of which is a server connected to a database and the other of which represents a user's client workstation, both of which are configured according to the present invention;

FIG. 6 represents an object model of the key tables in the relational database maintained on the server computer in the preferred embodiment of the present invention;

FIG. 7 represents a pseudo graphical user interface in which a user enters information in specific data fields to create a personal data record;

FIG. 8 represents a pseudo graphical user interface for listing other users with the same group affiliation as that specified by a first user;

FIG. 9 represents a pseudo graphical user interface for specifying what type of data fields from a first user's personal data record to which the first user wishes to grant a specific second user access;

FIG. 10 represents a pseudo graphical user interface that displays the information stored in a user's personal address book;

FIG. 11 represents a pseudo graphical user interface that provides a first user with specific information that has changed about the other users to which the first user is linked;

FIG. 12 represents a pseudo graphical user interface that allows a first user to enter travel information and find out which contacts have overlapping travel schedules;

FIG. 13 represents a pseudo graphical user interface that allows a first user to gather information about the contacts of his contacts; and

FIG. 14 is a data flow diagram of an alternative embodiment of the present invention where a personal digital assistant is synchronized with a server database of user information.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying figures. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

As represented in FIG. 5, the preferred embodiment follows a standard Internet architecture, in which client computers 370 and a server computer 330 are connected via the World Wide Web 360 and modems 338, 378 or other communications channels. A user accesses the server 360 via a client computer 370 operating a web browser 382 or other software application residing in memory 374 that allows it to display information downloaded from a server computer 330. The server computer system 330 runs server software 342, including the network-computer-based personal contact manager 343 of the present invention, which interacts with the client computers 370 and a user information database 340. In a commercial embodiment of the present invention, the personal contact manager 343 is the heart of a Web-based personal contact management service called PlanetAll. The database 340 contains contact information entered by registered users. The personal contact manager 343 in some situations will notify a set of users of updates made to the database 340 by another user to whom the notified set is related.

The database 340 in is a relational database built from a set of relational tables 350. In the conventional manner, both the server 330 and the clients 370 include respective storage devices, such as hard disks 336 and 376 and operate under the control of operating systems 344, 384 executed in RAM 334, 374 by the CPUs 332, 372. The server storage device 336 stores program files 346 and the operating system 348. Similarly, the client storage devices 376 store the web browser software 386 and the operating systems 388. In an alternative configuration, in which the client is a personal information manager (PIM), such as the U.S. Robotics Palm Pilot, the disc 376 can also include a local PIM database 390 and PIM software, which performs data management and synchronization functions.

FIG. 6 outlines the data structure of the relational database 340 in the preferred embodiment, in which seven tables 350 are employed to enable most of the functionality of the system:

(1) Customer Table 440;

(2) Friend Table 460;

(3) Group Table 400;

(4) Affinity Table 420;

(5) Address Table 480;

(6) Phone Table 500; and

(7) Travel Event Table 520;

The Customer Table 440 contains one record for each unique user. The key field in this table is CustomerID 440-2. All information stored in the various database tables relating to a particular member is linked together by a unique number in this field. Other important fields in this table include information used by users to login to the system (Username 440-6 and Password 440-8), information which helps users identify each other (First Name 440-10, Last Name 440-12, and E-mail 440-20), information required to provide Birthday Notification (Birthday 440-16) and information required to provide Crossing Paths notification (CityID 440-14). Each record in the Customer Table 440 is time-stamped via the RecordDate field 440-4. Other fields 440-22 can also be included in the Customer Table 440 (and the other tables as well).

The Friend Table 460 relates users to each other. Each record in the table represents a relationship between one user, identified by CustomerID 460-4, and another, identified by FriendID 460-6, with a certain level of permissions 460-10. The user interface of the system provides a multitude of ways for users to view information about other users, and every one of these ways relies on a database query of the Friend Table 460 to determine the list of other users whose information a particular user may see. Each record is time-stamped via the RecordDate field 460-8 so that users may be notified when their contacts' records change. Each record is uniquely identified by a RelationID 460-2.

The Group Table 400 contains one record for each unique group with which users may affiliate. Each group is identified by a GroupName 400-4 and GroupType 400-6. Examples of these groups would be GroupName 400-4=“Massachusetts Institute of Technology” (GroupType=“University”) and GroupName 400-4=“Sigma Chi” (GroupType=“Fraternity”). Each record has a time-stamp 400-8 and a unique identifier 400-2.

Each record of the Affinity Table 420 relates a user, identified by CustomerID 420-4, to a group, identified by GroupID 420-6. If a user affiliates with six groups, there would be six records in the Affinity Table 420. This table stores information about the time period of a user's affiliation with a particular group in the FromYear and ToYear fields 420-8, 420-10 so that the system may help users find their contemporaries. Each record is time-stamped 420-12 so that the system may report to users when other users join the group, has a unique identifier 420-2 and can include additional fields 420-14.

The Address Table 480 stores information for any number and kind of addresses for a particular user, identified by CustomerID 480-4. For instance, if a user wants to make his home address, work address and summer home address available to his contacts, there would be three records for that user in the Address Table 480, each being identified in part by an appropriate AddressType 480-8 (e.g., home, work, summer home). Each record is time-stamped 480-16 so that the system can notify users when their contacts have added or modified address information and has a unique identifier 480-2. Address information is conventional, including street Address 480-8, CityID 480-10, Postal code 480-12, and military Base 480-14 fields.

The Phone Table 500 is directly analogous to the Address Table 480, but it stores telephone and fax number information instead of address information. Each record is identified by a unique PhoneRecordID 500-2 and includes the CustomerID 500-4 of the user whose phone information is contained in the record, a phone type ID 500-6 indicating, e.g., whether the record is for a telephone or fax, the phone number 500-8 and a time-stamp 500-10.

The Travel Event Table 520 stores information about users' travel plans. This table is required to notify users when their travel plans intersect with the travel plans of their contacts. A record in the Travel Event Table 520 includes the CustomerID 520-4 of the user whose travel information is contained in the record, arrival and departure dates 520-6, 520-8 and a CityID 520-10 identifying the travel destination. Each record is uniquely identified by a Travel_EventID 520-2 and is time-stamped with a RecordDate 520-14.

In the preferred embodiment, a multitude of other tables 540 are used to enable a variety of user services. The Permission Type Table 542 contains one record for each of the varieties of permission levels the system allows members to assign to their contacts in the Friend Table 460. In the preferred embodiment, as illustrated in FIG. 9, permission information is grouped into five categories for the purpose of user interface simplicity (crossing paths notification permission 600-6, personal information 600-8, work information 600-10, birthday notification 600-12, and friends of friends information 600-14). However, the Permission Type table 542 could just as easily be structured to allow members to grant and deny access to information on a field by field basis.

The City Table 550 stores latitude and longitude information for two million cities to enable the system to notify users when their contacts travel within a defined geographical radius. The Zodiac Table 552 allows the system to associate birthdays with signs of the Zodiac and thereby notify which of their contacts have compatible astrological signs on a particular day. The AddressType, PhoneType and GroupType tables 544, 546, 548 define the types of address, phone and group that can be defined in the respective Address, Group and Phone tables 480, 400, 500. The advantage of this normalized relational database architecture is that it permits scaling and speed far in excess of any embodiment of the prior art.

FIGS. 7 through 12 display pseudo software graphical user interfaces (GUIs). In the preferred embodiment, the web server software 342 on the server computer 330 displays these GUIs via the computer communications interface 360 on the user interface 380 of the user workstation computer 370. The database and communications operations necessary to perform the described functions are controlled by the personal contact manager 343, which employs where necessary the services of the web server software 342. For example, the personal contact manager 343 updates the database tables 350 when a user submits a new home address and then determines whether any of that user's contacts need to be notified of the change. If so, the personal contact manager 343 will issue the notifications via the web server software 342. It should be assumed, unless a statement to the contrary is made, that all of the operations described herein which are aspects of the present invention are embodied by the personal contact manager 343.

Referring now to FIG. 7, a pseudo GUI 560 is shown that allows members to enter information about themselves in order to create a personal data record. Users can enter information in this GUI in various data fields. In the preferred embodiment, these fields include: Name 560-2, Home Address 560-4, Home Phone 560-6, Work Address 560-8, Work Phone 560-10, Birthday 560-12, High School 560-14, Year of High School Enrollment 560-16, High School Graduation Year 560-18, College 560-20, Year of College Enrollment 560-22, and College Graduation Year 560-24.

In certain of these data fields, the user can specify groups with which he wishes to affiliate himself, and the beginning and ending dates of the affiliation. In the preferred embodiment, the data fields High School 560-14 and College 560-20 represent categories of groups. In the data field Year of High School Enrollment 560-16, the user enters the beginning date of the affiliation with the group specified in the data field High School 560-14. In the data field High School Graduation Year 560-18, the user enters the ending date of the affiliation with the group specified in the data field High School 560-14. In the data field Year of College Enrollment 560-22, the user enters the beginning date of the affiliation with the group specified in the data field College 560-20. In the data field College Graduation Year 560-24, the user enters the ending date of the affiliation with the group specified in the data field College 560-20. In both of these cases, the beginning date and ending date establish a date range during which time the user was affiliated with the group in question.

Once the user of the client computer 370 (FIG. 5) enters information in each data field in the GUI 560 shown in FIG. 7, he clicks the Submit button 560-26 (or performs some equivalent action) and the information entered is transferred via the computer communications network 360 (FIG. 5) to the server computer 330, where the server personal contact manager software 343 stores the information in the appropriate tables 350 of a database 340.

Referring now to FIG. 8, a pseudo GUI 580 is shown that allows a first user to select other users they wish to add to their personal address book. The list of contacts is created based on the group affiliation information the first user enters in the data fields College 560-20, Year of College Enrollment 560-22, and College Year of Graduation 560-24 in the Pseudo Registration GUI 560 shown in FIG. 7. A similar GUI 580 would exist for the group specified in the data field High School 560-14 in the pseudo 560 GUI shown in FIG. 7.

In each version of the GUI 580 shown in FIG. 8, a text description 580-2 at the top of the GUI explains to the first user that other members have been found who had the same affiliation as the first user during the same period of time as the first user. The name 580-6 of the group in which the first and second users share an affiliation is displayed and the date range 580-8 of the first user's affiliation with that group is displayed.

If a second user whose personal information is stored in the tables 350 of the database 340 on the server computer 330 has specified the same group affiliation as that specified by the first user in the College 560-20 data field, and that second user has specified a date range for that affiliation that intersects with the date range specified by the first user in the Year of College Enrollment 560-22 and College Graduation Year 560-24 data fields, the Name 580-10 of the second user and the ending date 580-12 of the second user's affiliation with that group are displayed.

A second text description 580-4 at the top of the GUI 580 instructs the first user to select any of the second users listed whom the first user wishes to add to his personal address book. If the first user wishes to add a second user to his personal address book, the first user clicks the checkbox 580-14 to the left of the Name 580-10 (e.g., “John Doe”) for that second user. Once the first user has finished specifying the users he wants to add to his address book, he clicks the Submit button 580-16, and the information entered is transferred via the computer communications network 360 to the server computer 330 where it is stored in the appropriate tables 350 of the database 340.

A pseudocode description of the actions performed by the personal contact manager software 343 to display the group member list is shown in Appendix A. This pseudocode fragment (and the others that follow) is written in a structured English that is similar to computer languages such as Pascal, FORTRAN and C. The pseudocode fragments are not described herein as they are self-explanatory. The tables and fields referred to in the pseudocode fragments correspond to the tables and fields described in reference to FIG. 6.

Referring now to FIG. 9, a pseudo GUI 600 is shown allowing a first user to specify which types of data fields from the first user's personal data record to grant a specific second user permission to view. If a first user specifies a second user whom the first user would like to add to his personal address book, as explained in the description of FIG. 8, the second user will receive notification (issued by the contact manager program 343—FIG. 5) that the first user has “linked” to him. If the second user chooses to return the link to the first user, the system will display the pseudo GUI 600 shown in FIG. 9 with the name of the first user 600-5, allowing the second user to set data field permissions for the first user. Unlike the prior art, which does not allow the first user to specify data field permissions for individual other users, the disclosed system allows the first user to specify permissions separately for each individual other user in whose personal database the first user has chosen to be included.

A text description 600-2 at the top of the pseudo GUI in FIG. 9 instructs the first user to specify which types of data fields from the first user's personal data record to allow to appear in the personal address book of the second user, whose name 600-4 is shown below. Several types of data field permission are listed, each with a check box to the left enabling the first user to select or deselect the permission type. For example, to grant the second user 600-4 permission to view the information from the first user's personal data record indicated by the permission type denoted “Crossing Paths Notification Permission,” the first user would check the box 600-7 to the left of the permission type Crossing Paths Notification Permission 600-6. To deny the second user 600-4 permission to view the information from the first user's personal data record indicated by the permission type denoted “Personal Information,” the first user would uncheck the box 600-9 to the left of the permission type Personal Information 600-8.

In the preferred embodiment of the present invention, the levels of permission are as follows: Crossing Paths Notification Permission 600-6, Personal Information 600-8, Work Information 600-10, Birthday Notification 600-12, and Friends of Friends Information 600-14. However, the present invention is not limited to the levels of permission shown in the preferred embodiment. The present invention is flexible to allow permission categories to be modified as needed.

Each permission type allows the second user to view information from the first user's personal data record in specific data fields, according to a specific set of rules. In the preferred embodiment of the present invention, these permission rules are as follows:

If member A links to member B, member A can grant any of the permissions discussed below to member B.

Even if member B does not reciprocate the link to member A, an e-mail forwarding address for member B will be included in the Virtual Address Book for member A. For example, the e-mail address “memberB@planetall.com,” which maps to the actual e-mail address that member B has entered into his/her own record, will appear in member A's Virtual Address Book, but nothing else.

When member A first links to member B, member B is notified on the Web site and in an e-mail.

If member B elects not to grant any permissions to member A, member A will not appear in member B's Virtual Address Book.

If member B grants any permissions to member A, a listing in member B's Virtual Address Book will be created for member A, and the listing will contain whatever information member A has given permission for member B to see.

If member B grants Personal Information 600-8 permission to member A, member B's home address and phone number (if available) will appear in member A's Virtual Address Book and member A will be informed when member B changes the relevant information in his/her own listing.

If member B grants Work Information 600-10 permission to member A, member B's work address and phone number (if available) will appear in member A's Virtual Address Book and member A will be informed when member B changes the relevant information in his/her own listing.

If member B grants Crossing Paths Notification Permission 600-6 to member A, member A will be able to be informed when member B will be in the same city as member A. If member A and member B are both based in the same city, member A will only be informed when member A and member B are traveling to the same destination.

If member B grants Birthday Notification 600-12 permission to member A, member B's birthday and anniversary (if available) will appear in member A's Virtual Address Book and member A will be notified when member B's birthday or anniversary are approaching.

If member B grants Friends of Friends Information 600-14 permission to member A, if member A searches for information about the contacts of his/her contacts, such as who lives in a particular city or is associated with a particular group, information from member B's circle of contacts will be included in the search results, if applicable.

Either member can modify permissions at any time. Either member can delete the other member as a contact at any time.

Pseudocode descriptions of the actions performed by the personal contact manager software 343 to display address information of contacts and to perform birthday and address change notifications are shown in Appendices B, C and D, respectively. Each of these operations depends on which permissions respective users have been granted by the owner of the information.

Once the first user has finished specifying the data field permissions for the second user 600-4, he clicks the Submit button 600-16 and the information entered is transferred via the computer communications network 360 to the server computer 330 where it is stored in the appropriate tables 350 of the database 340 (see FIG. 5). A pseudocode description of the actions performed by the personal contact manager software 343 to enable a user to change the permissions of contacts is shown in Appendix H.

Referring now to FIG. 10, a pseudo GUI 618 that displays the information stored in a user's personal address book is shown. The information in a user's personal address book is stored in the appropriate tables 350 of the database 340 on the server computer 330, to which the client computer 370 is connected via the world wide web 360 (see FIG. 5). The information in each user's personal address book is customized for that user, as described below. Each first user's personal address book contains information about each second user who has given the first user permission to view information in the second user's personal data record 636. Which categories of each second user's information are displayed in the first user's personal address book is controlled completely by the second user, as explained in the description of FIG. 9. In addition, each second user's information is entered and maintained completely by the second user (e.g., “Donald Tully”), as explained in the description of FIG. 7.

FIG. 10 illustrates the Address Book pseudo GUI 620 at three levels, in which each next level allows the user to view progressively more detail about the contacts in his personal address book.

In level 1 620 of the pseudo address book GUI 618, each letter of the alphabet is shown 622. By clicking on any letter of the alphabet 622, a first user can display a listing of the contacts whose last names begin with the letter of the alphabet selected, and about whom information is stored in the first user's personal address book. This information is displayed in the level 2 626 of the pseudo address book GUI. For example, if the first user clicks on the letter “T” 624 in level 1 620 of the pseudo address book interface, all contacts whose last names begin with the letter T and about whom information is stored in the first user's personal address book will be displayed 628 in level 2 626 of the pseudo address book GUI.

In level 2 626 of the pseudo address book GUI, a listing of the second users whose last names begin with the letter of the alphabet selected in level 1 620 of the pseudo address book GUI, and about whom information is stored in the first user's personal address book, is shown. By clicking on any second user's name, the first user can display the information about that second user stored in the first user's personal address book. This information is displayed in level 3 632 of the pseudo personal address book GUI. For example, if the first user clicks on the second user name “Tully, Donald” 630, the information pertaining to Donald Tully stored in the first user's personal address book will be displayed in level 3 632 of the pseudo address book GUI.

In level 3 632 of the pseudo address book GUI, information 634 is shown about a specific second user that is stored in a first personal address book. Only the categories of information from the second user's personal data record that the second user gave the first user permission to view are displayed. The second user's information is entered and maintained completely by the second user.

In the preferred embodiment of the present invention, the second user's e-mail address 634-2 is displayed if the second user gave the first user any type of data field permission. The second user's work address and phone number 634-4 are displayed only if the second user gave the first user Work Information permission. The second user's home address and phone number 634-6 are displayed only if the second user gave the first user Personal Information permission. The second user's birthday and birth year 634-8 are displayed only if the second user gave the first user Birthday Notification permission. These permission rules are simply examples from the preferred embodiment. The present invention is not limited to the permission rules used in the preferred embodiment.

A pseudocode description of the actions performed by the personal contact manager software 343 to display the address book listing is shown in Appendix B.

Referring now to FIG. 11, a member update pseudo GUI 650 is shown. This pseudo GUI 650 provides a first user with specific information that has changed about the other users to which the first user is linked, plus new information about contacts to whom the first user may wish to link. The information displayed in a user's member update is stored in the appropriate tables 350 of the database 340 on the server computer 330, to which the client computer 370 is connected via the world wide web 360. The member update pseudo GUI 650 is automatically displayed on the user interface 380 of the user workstation 370, at an interval preset by the user. For example, FIG. 11 displays a hypothetical member update 650-2 released on Dec. 7, 1998. The information displayed in the data fields below is information that has changed between Dec. 7, 1998 and the date of the previous update, the interval between which has been previously specified by the user. The information shown in each user's member update is customized for that user, as described below.

In a first portion of the member update pseudo GUI 650 shown in FIG. 11, if one or more of the second users who have linked to a first user and have provided Birthday Notification permission to the first user have upcoming birthdays, a text description 650-4 alerts the first user of the upcoming birthday(s). The names and birthdays 650-6 for those second users are listed below. In the preferred embodiment of the present invention, the first user will receive this notification 2 weeks, 1 week, 2 days, and 1 day in advance of a particular upcoming birthday, and on the actual date of the birthday. The first user does not need to collect and input the birthday dates for each second user who has linked to the first user. Each second user's birthday information is entered and maintained completely by the second user, as shown in the Birthday field 560-12 of FIG. 7, the registration form pseudo GUI 560.

In another portion of the member update pseudo GUI shown in FIG. 11, if one or more of the second users who have linked to the first user and have provided Personal Information permission or Work Information permission to the first user have changed their work or home address, a text description 650-8 alerts the first user. If a second user has changed his work address information and has given the first user Work Information permission, the second user's new work address information 650-10, 650-12 is displayed. If a second user has changed his home address information and has given the first user Personal Information permission, the second user's new home address information is displayed.

Each second user's address information is entered and maintained completely by the second user, as shown in the registration form pseudo GUI 560 of FIG. 7. After changing his address information in his personal data record, the second user does not need to specify that the new address information be provided to each first user to whom he has linked and given the proper form of data field permission. The new address information is provided to each first user quickly and automatically. In addition, the architecture of the present invention is scalable to include millions of users.

In another portion of the member update pseudo GUI 650 shown in FIG. 11, if one or more members has affiliated with a group with which the first user is also affiliated, a text description 650-14 will alert the first user. The name of the second user, the name of the group in which the first and second users share an affiliation, and the ending date of the second user's affiliation with that group are displayed 650-16.

This portion of the registration form pseudo GUI 650 functions similarly to the group list form pseudo GUI shown in FIG. 8. If a new second user who fills out a registration form such as the pseudo GUI in FIG. 7, and therefore whose personal information is stored in the tables 350 of the database 340 on the server computer 330 has specified the same group affiliation as that specified by the first user in the College 560-20 data field, and that second user has specified a date range for that affiliation that intersects with the date range specified by the first user in the Year of College Enrollment 560-22 and College Graduation Year 560-24 data fields, the Name of the second user and the ending date of the second user's affiliation with that group 650-16 are displayed. Similarly, if the first user and the new second user were affiliated during an intersecting period of time with the group specified in the data field High School 560-14 in the pseudo GUI 560 shown in FIG. 7, the Name of the second user and the ending date of the second user's affiliation with that group 650-16 are displayed.

A pseudocode description of the actions performed by the personal contact manager software 343 to display a list of service members who have recently joined a user's groups (i.e., members who are not current contacts of the user) is shown in Appendix E.

If the first user wishes to add contact information to his personal address book for any of the second users listed 650-16, the first user can do so in a GUI similar to the group list form pseudo GUI 580 shown in FIG. 8. Each second user to whom the first user has initiated a link will then be informed of the link, and can then return the link and specify data field permissions for the first user, if any, as explained in the description of FIG. 9.

A pseudocode description of the actions performed by the personal contact manager software 343 to identify people who have linked to a particular user are shown in Appendix F.

In another portion of the member update pseudo GUI 650 shown in FIG. 11, if a second user has initiated a link to a first user, the first user will be automatically notified 650-18 that a link has been made. For each second user that has initiated a link, the user's name 650-20 is shown. If the first user wishes, the first user can then return the link and specify data field permissions for the second user, if any, as explained in the description of FIG. 9.

Another section 650-22 of the member update pseudo GUI 650 shown in FIG. 11 is used to inform a first user when the travel plans he has entered into the system overlap with the travel plans that any of his contacts has entered into the system, as long as the contact has granted the first user Crossing Paths Notification permission.

This system, termed “Crossing Paths Notification” in the preferred embodiment of the present invention, operates as follows. The home city or “base city” for each user is determined from information entered by that user in the Home Address data field 560-4, as explained in the description of FIG. 7. The “City” table 550 (FIG. 6) stored on the server computer 330 includes 1.7 million names of cities around the world. Each of these cities is associated with a precise latitude and longitude. If the user's base city cannot be matched to a city in the “City” table, the user can add the new city to the “City” table by giving the name of another city that is already in the “City” table that is nearby the user's base city. The user's base city is assigned the same latitude and longitude as the existing city. This information is used to associate each user with a precise longitude and latitude, and determine all cities within a 29-mile radius of the user's base city.

Whenever a user is planning to travel, he can specify the dates during which he will be away and the city he will be visiting. If a second user has granted a first user Crossing Paths Notification permission, and the first user has entered a Travel Event to a city that is within a 29-mile radius of the base city of the second user, the first user will be notified 650-22 (FIG. 11) that he will be crossing paths with the second user 650-24 (e.g., “Andrew Kress”), as long as the second user has not also scheduled a travel event for the same time period. In another scenario, if a second user has granted a first user Crossing Paths Notification permission, and the first user has entered a travel event to a city that is within a 25-mile radius of a city to which the second user has scheduled a travel event during the same time period, the first user will be notified 650-22 that he will be crossing paths with the second user 650-24. Travel events are described more fully in reference to FIG. 12.

The Crossing Paths Notification system is able to handle multiple cities in a single day. For instance, if a first user lives in Boston but is traveling to New York on March 5, then the first user will be informed if any contacts will be crossing paths on that day in either city. In addition, this system is scalable to millions of users. A pseudocode description of the actions performed by the personal contact manager software 343 to enable a user to receive crossing paths notification is shown in Appendix I.

The final section 650-26 of the member update pseudo GUI 650 shown in FIG. 11 is used to inform a first user which of his contacts has an astrological sign compatible with that of the first user on the date of the member update. Each member is associated with one of the twelve astrological signs based on the information he entered in the Birthday data field 560-12 in the registration form pseudo GUI 560 shown in FIG. 7. Each day of the year is mapped to one of these twelve signs. This information is stored in the appropriate table 350 in the database 340 on the server computer 330. On a given day, all of a member's contacts who are associated with “sign of the day” are deemed to be compatible with the member. Only the names of contacts who have given the first user Birthday Notification permission will be shown in the member update pseudo GUI for the first user. A pseudocode description of the actions performed by the personal contact manager software 343 to enable a user to receive notification of compatible contacts is shown in Appendix J.

The permission rules used in reference to FIG. 11 are simply examples from the preferred embodiment. The present invention is not limited to the permission rules used in the preferred embodiment.

Referring now to FIG. 12, a pseudo Add Travel Form GUI 660 and a pseudo Crossing Paths List GUI 670 are shown. These two screens are used in the Crossing Paths Notification System. If a first member is planning a trip, the first member can use the pseudo Add Travel Form GUI 660 to add a Travel Event, in which he specifies the location 660-2, 660-4, 660-6, dates 660-8, 660-10, and contact information 660-20 for the intended trip. In the pseudo Crossing Paths List GUI 670, the first member is informed which of the second members to whom he is linked and who have granted him Crossing Paths Permission will be in the vicinity of the city to which the first user is travelling, during the time period of the specified Travel Event. The first user can then use the pseudo Crossing Paths List GUI 670 to select which of the displayed second users the first user would like to inform of the first user's specified Travel Event.

The pseudo Add Travel Form 660 is displayed on the user interface 380 (FIG. 5) of a user's client computer 370 when the user chooses to schedule a Travel Event. The user enters information about his scheduled trip in the data fields shown. In the Traveling To City field 660-2, the user enters the name of the city to which he is traveling. In the State field 660-4, the user enters the name of the state in which is located the city to which he is traveling. In the Country 660-6 field, the user enters the name of the country in which the city to which he is traveling is located. The information entered in these three fields 660-2, 660-4, 660-6 is used to locate the city for the Travel Event in the City table 550 on the server computer 330. The exact latitude and longitude of the Travel Event city is then determined and a list is created of all cities located within a 25-mile radius of the Travel Event city. In the Arrive in City on Date field 660-8, the user enters the first date on which he will be in the Travel Event city. In the Leave City on Date field 660-10, the user enters the date beginning on which he will no longer be in the Travel Event city. The information entered in these two fields 660-8, 660-10 is used to determine the date range for the Travel Event. Finally, in the How to Get in Touch While in This City data field 660-20, the user enters the method for contacting him during the Travel Event. After the user has finished entering information in the pseudo Add Travel Form GUI (12-1), the information entered is stored by the personal contact manager 343 in the Travel_Event table 520 on the server computer 330.

The pseudo Crossing Paths List 670 is displayed on the user interface 380 of the first user's client computer 370 after a first user has scheduled a Travel Event using the pseudo Add Travel Form 660. A text message 670-2 issued by the personal contact manager 330 informs the first user that one or more of his contacts will be in the same city as the first user during the first user's scheduled Travel Event. Those contacts (e.g., Scott Ulem, Taylor Pierce, Betsy Klein) who live in the city of the first user's scheduled Travel Event are listed 670-6, as well as those contacts (e.g., Tania Gutsche) who will be visiting the city of the first user's scheduled Travel Event 670-8. The contacts listed in the field 670-6 are those second users who have granted the first user Crossing Paths Permission, and who have listed in the Home Address field 560-4 (FIG. 7) of their Personal Data Record the city of the first user's scheduled Travel Event, or any city within a 25-mile radius of the first user's scheduled Travel Event. The contacts listed in the field 670-8 are those second users who have granted the first user Crossing Paths Permission, and who have scheduled a Travel Event to the city of the first user's scheduled Travel Event, or any city within a 25-mile radius of the first user's scheduled Travel Event, during the date range of the first user's scheduled Travel Event. For each contact name listed in both fields 670-6, 670-8, the first user can choose to inform that contact of the first user's scheduled Travel Event by clicking on the checkbox to the left of that contacts name. When the first user is finished selecting contacts, he then clicks the Submit button 670-10, which copies the information entered to the server computer (5-45) to be stored in the tables 350 by the networked personal contact manager 343. For each second user whom the first user selected, the second user is informed, in a screen similar to the pseudo Member Update GUI shown in FIG. 11, of the first user's Travel Event and the means of contacting the first user 660-20 during the Travel Event.

Referring now to FIG. 13, a diagram illustrating the Friends of Friends system is shown. The Friends of Friends system allows a first member to search for the names of contacts of their contacts who live in the same city as the first member or are affiliated with a group with which the first member is also affiliated. When a first user performs a Friends of Friends search, the personal contact manager 343 displays, via the web server software 342, the results of the search on the user interface 380 (FIG. 5) of the first user's client computer 370 in a GUI similar to the pseudo Friends of Friends report GUI 688. After locating a second member who is a friend of a friend, the first member can then link to that second member in order to add the second member to the first user's Personal Address Book, as explained in the descriptions of FIG. 8 and FIG. 9 above.

In the preferred embodiment of the personal contact manager 343, the Friends of Friends system operates as follows. If a Member A 680 is linked to a Member B 682 with any level of permissions 681 and the Member B 682 is linked to a Member C 684 with any level of permissions 685, then if Member C 684 grants to Member B 682 Friends of Friends permissions 687 and Member B 682 also grants to Member A 680 Friends of Friends permissions 683, then Member A is eligible to receive Friends of Friends notification about Member C. When a first user performs a Friends of Friends search, the results of the search will include all second users who have affiliated themselves with a group with which the first user is affiliated and all second users who live in the same city in which the first user lives, so long as the first user is eligible to receive Friends of Friends notification about those second users, as described above. For example, if Member A and Member C both belong to Group A 686, and Member A is eligible to receive Friends of Friends notification about Member C, then the result of Member A's Friends of Friends search 688 generated by the personal contact manager 343 will include Member C 690.

A pseudocode description of the actions performed by the personal contact manager software 343 to perform a search for friends and friends of friends in a specific city is shown in Appendix G.

The present invention is not limited to the search criteria or levels of separation in the preferred embodiment. The database architecture in the present invention is flexible to allow searches to be extended to more than one degree of separation. For instance, it would be possible to add a Friends of Friends of Friends search feature. The architecture is also flexible to allow new search criteria to be added.

Referring to FIG. 5, in each of the embodiments described above, the user information is stored on the server 330 and all user access to the user information is mediated by a client web browser 382, the web server software 342 and the server personal contact manager software 343. In an alternative embodiment, which is configured for personal information managers (PIMs), such as the U.S. Robotics Palm Pilot, a user is able to synchronize their user information and their PIM database 390 through an importation/synchronization function performed by the personal contact manager software 343. The synchronization operation can be performed in either direction (i.e., client to server or server to client). The server personal contact manager software 343 will then use the web server software 342 to communicate with the PIM software 392 of the user's contacts, if applicable, and, in accordance with the permission scheme already described, synchronize the databases 390 in the contacts' PIMs. All database, personal contact management and linking operations already described are operable in the alternative embodiment, except the GUIs might be different, depending on the graphical capabilities of the client 370 running the PIM program 392. Thus, the alternative embodiment allows full synchronization of PIMs and the server database 340.

A data flow diagram illustrating the operation of the alternative embodiment is shown in FIG. 14. In the illustrated situation a user A submits an address change from their client computer 370A. In response to the update, the personal contact manager 343 running on the server 330 updates user A's address information in the server database 340 (not shown) and issues an update notification to the client computer 370B used by user B, who is a contact of user A. This alternative embodiment assumes that user B has a PIM (also referred to as a personal digital assistant or PDA) that they would like to synchronize with the server database 340. In such a case PIM Software 392 running on the client 370B performs the synchronization operation based on the user A address update information provided by the server 330. Following the synchronization operation, the PDA database 390 has the same information for user A as the server database 340. Alternatively, the PDA 750 can be coupled directly to the Internet (indicated by the dashed line), in which case it operates substantially as a typical client computer 370 described in reference to FIG. 5. However, one difference is that the PDA 750 maintains its own database 390 instead of relying solely on the server database 340.

While the present invention has been described with reference to a few specific embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Appendix A Display Group Member List

Submit group name.

Match group name to GroupID in Group table.

Join Affinity table to Customer table and CustomerPrefs table based on CustomerID.

Show contact information from Customer and CustomerPrefs tables when the Affinity table contains a record matching the CustomerID to the specified GroupID.

APPENDIX B Display Address Book Listing If MemberFriend AND a Reciprocated Link then If have Personal or Professional Permissions then Show person's real email address. else Show person's PlanetAll address. end if If have Personal Permission and Biography Exists then Show Biography. end if If (have Personal or Professional Permissions) AND universal resource locator (URL) exists then Show URL. end if If (Person is visible in group and Group Perms > 0) AND you have Common Groups then Show the groups you have in common. end if If Person is in one of more of your personal email lists then Show the lists the person belongs to. end if If have Personal Permissions and Phone Type is one of personal phone types then Show phone. end if If have Professional Permissions and phone type is one of professional phone types then Show phone. end if If have Personal Permissions and address Type is one of personal address types then Show address. if address is in USA then Show map link. end if end if If have Professional Permissions and address type is one of professional address types then Show address. if address is in USA then Show map link. end if end if If have Professional Permissions and Professional Info Exists then Show the professional info the person has entered. end if If have Occasions Permissions and Birthday exists then Show the contact's birthday. end if If have Occasions Permissions and Anniversary exists then Show the contact's Anniversary. end if If contact has entered spouse's name then Show spouse's name. end if If contact has entered self description then Show self description. end if else if MemberFriend AND a Non-Reciprocated Link then Show message person has not linked back and give link so person can email the unlinked person to tell them they have linked to them, (after com/ASP rewrite will not show email so spammers can't make lists). end if

Appendix C Birthday Notification

Birthdays are determined by the DayOfYear field in the customers table. Create a list of all my contacts:

-   -   Go to the Friend table and select all Customers where         FriendID=my CustomerID.         For each of my contacts, check to see if the DayOfYear is within         seven days of the current DayOfYear.

-   Select the DayOfYear from the Customers table for all of the     customers in my list of contacts.

-   If the DayOfYear is within seven days of the current DayOfYear, then     select the name of the customer.     Display the names of all my contacts who have birthdays in the next     seven days.

Appendix D Address Change Notification

To determine which of a member's contacts' addresses have changed: Create a list of all my contacts:

-   -   Go to the Friend table and select all Customers where         FriendID=my CustomerID.         Find out which of these contacts have changed their addresses:     -   Link the Customers table and find records for my contacts where         AddressID is greater than the lowest Address ID having a date         greater than the date on which my last email update was sent.         Find out which of these contacts have given me permission to see         the address information that has changed:     -   Make sure that the appropriate permission appears in the record         in the friend table linking me to the contact.         Display information for these contacts.

Appendix E Show New Group Members

Create a list of all my groups:

-   -   Go to the affinity table and select all the records for my         CustomerID Select the GroupID for each of the records.     -   Do not include other customers' private groups to which I have         been added For each of my affinity records, check to see that         Group Perms are >0.         Create a list of all my contacts:     -   Go to the Friend table and select all Customers where         FriendID=my CustomerID.         Create a list of people who joined my groups:     -   Go to the affinity table and select all the affinity records for         my groups.     -   Select only affinity records for customers who joined the group         after I joined.         -   Select affinity records where the date of the record is             after the date for my affinity record in the same group.         -   Select only affinity records for people who joined the             groups after my last email was sent.         -   Select affinity records where the date of the record is             after my Sent date in the Email table.     -   Do not include people that are in my list of contacts:         -   Select only affinity records where the CustomerID is not             included in the list of all my contacts.     -   Select the CustomerID from each affinity record in the list of         people who joined my groups.     -   Go to the Customers table to find the name of each customer who         joined my groups.

Appendix F People Who Have Linked To You

Linking the Friends table and the Customers table based on the CustomerID field, select the following information from the two tables:

CustomerID from the Friends table.

First Name from the Customers table.

Last Name from the Customers table.

Record Date from the Friends table.

Permission level from the Friends table.

Where my CustomerID is not among the CustomerIDs found in the following search:

CustomerID in the Friends Table is my CustomerID

AND the Record Date from the Friends table is within the last 30 days AND I haven't already linked to the person

Appendix G Search for Friends of Friends in a Particular City

Specify City. Match to CityID in City table. Create a list of all my contacts Go to the Friend table and select all Customers where FriendID=my CustomerID Make a temporary table linking the Friends table to itself called Friend_1 and establish the following relationships:

-   CustomerIDs for the contacts of my contacts appear in the Customer     field of the Friends table -   CustomerIDs for my contacts appear in the Friend field of the     Friends table -   CustomerIDs for my contacts also appear in the Customer field of the     Friends_1 table (this is how the tables are joined) -   My Customer ID appears in the Friend field of the Friend_1 table -   The Friend and Friend_1 tables are joined on t     Show information for the contacts of my contacts (i.e. the Customers     from the Friends table) where the following conditions are true:     -   The Friends of Friends permission was granted from the contacts         of my contacts to my contacts.     -   The Friends of Friends permission was granted from my contacts         to me.     -   The contact does not already appear in the list of all my         contact created above.     -   The city for the contact of my contact matches the specified         city.

Appendix H Change Permissions

Join the Customer table to the Friend table based on CustomerID. Create a list of all my contacts:

Go to the Friend table and select all Customers where FriendID=my CustomerID.

Show First Name and Last Name for my contacts from the Customer table. Allow me to pick a name from this list as the contact whose permissions I would like to change. Display the permission level that I have given this contact. It is stored as the PermissionType field in the Friend table. Allow access to the PermissionType for this record in the Friend table.

Appendix I Crossing Paths Notification

Create a list of all my contacts:

-   -   Go to the Friend table and select all Customers where         FriendID=my CustomerID.         Create a list of all my contacts' travel events:     -   Go to the Queue Travel Event table and select all QueueIds where         the CustomerID is in my list of contacts.     -   Do not include trips for people who linked to me but did not         give me crossing paths permission:         -   Check the permissions field in the Friend table for each of             my contacts to see if I have crossing paths permissions.     -   Do not include trips if my contact specified that I should not         be informed:         -   For each of my contacts' trips, check the Travel Exception             table to see if my CustomerID is included in the list of             people who should not be informed of the trip.             Create a list of my location for the next seven days:     -   Select the arrival date, departure date, and city for all my         trips in Queue Travel Event for the next seven days.     -   For days when I am not traveling, select my city from the         customers table.         Select from the list of my friends' trips, all the trips to         cities that are within 3000 latitude and 3000 longitude to my         location for each of the next seven days.         Go to the Customers table and find the names of all the people         with whom I will be crossing paths.

-   Select first name and last name from the customers table for all the     CustomerIDs in the list of my contacts trips

Appendix J Compatible Contacts

Create a list of all my contacts:

-   -   Go to the Friend table and select all Customers where         FriendID=my CustomerID.         Determine my Zodiac sign:     -   Select my DayOfYear from the Customers table.     -   Select the Zodiac sign from the Zodiac table where my DayOfYear         is between the DayFrom and DayTo fields.         Determine my compatible Zodiac sign for today:     -   Go to the Horoscope table and select the Compatible field from         the row for my Zodiac sign and today's date.         Find my compatible contacts for today:     -   Select the DayFrom and DayTo fields from the Zodiac table for my         compatible zodiac sign.     -   Select my contacts from the list of all my contacts whose         DayOfYear is between the DayFrom and DayTo fields for my         compatible sign. 

1-9. (canceled)
 10. A method of facilitating meetings between social networking contacts, the method comprising: providing a computer-based service that enables users to selectively establish contact relationships with other users such that each user of the service can have one or more contacts; storing relationship data specifying contact relationships established between users of the service; storing data regarding locations of particular users of the service; detecting, based on the relationship data in combination with the data regarding the locations of users, a crossing paths event in which a first user and a second user who have a contact relationship with each other are concurrently in a common location; and sending a notification of the crossing paths event to at least the first user; said method performed in its entirety by a networked computer system.
 11. The method of claim 10, wherein the notification is sent based at least partly on a determination that the second user has granted permission via the service for the first user to be notified of a location associated with the second user.
 12. The method of claim 10, further comprising storing permission data that specifies whether the first user has granted permission for the second user to be notified by the service of location information associated with the first user.
 13. The method of claim 10, wherein the data regarding locations comprises travel event data.
 14. The method of claim 10, wherein the crossing paths event is an event in which the first and second users travel to said common location.
 15. The method of claim 10, wherein the crossing paths event is detected before the first and second users are concurrently in said common location.
 16. The method of claim 10, wherein the method is performed under control of program code executed by the networked computer system.
 17. The method of claim 10, wherein the method comprises establishing the contact relationship between the first user and the second user by a process that comprises, by said computer system: receiving a request from the first user to establish a contact relationship with the second user; sending to the second user a notification of the request; and receiving a reciprocating request from the second user to establish said contact relationship.
 18. A networked computing system, comprising: a server that provides network-based user access to a service interface that provides functionality for users to register with a service, and to selectively establish contact relationships with other users of the service, said server comprising a processor and memory; a computer data repository that stores relationship data that specifies contact relationships established between users of the service; and a notification service configured to use the relationship data, in combination with location data associated with users of the service, to detect an event in which a first user and second user who have an established contact relationship with each other are concurrently in a common location, said notification service additionally configured to notify at least the first user of said event.
 19. The networked computing system of claim 18, wherein the notification service is configured to send the notification based at least partly on a determination that the second user has granted permission via the service for the first user to be notified of a location associated with the second user.
 20. The networked computing system of claim 18, wherein the location data comprises travel event data.
 21. The networked computing system of claim 18, wherein the event is an event in which the first and second users travel to a common destination.
 22. The networked computing system of claim 18, wherein the notification service is configured to detect the event before the users are concurrently in said common location.
 23. Non-transitory computer storage having stored thereon executable program instructions that direct a computer system to perform a process that comprises: providing a user interface that includes functionality for users of a service to selectively establish relationships with other users of the service; storing relationship data specifying the relationships established between users of the service; storing location data associated with particular users of the service; identifying, based on the relationship data, a first user and a second user that have an established relationship; detecting, based on the location data associated with the first and second users, an event in which respective locations of the first and second users coincide; and sending a notification of the event to at least the first user.
 24. The non-transitory computer storage of claim 23, wherein the notification is sent based at least partly on a determination that the second user has granted permission for the first user to be notified of a location associated with the second user.
 25. The non-transitory computer storage of claim 23, wherein the location data comprises travel event data.
 26. The non-transitory computer storage of claim 23, wherein the event is based on a determination that the first and second users are scheduled to travel to said common location.
 27. The non-transitory computer storage of claim 23, wherein the process comprises establishing the relationship between the first user and the second user by a process that comprises: receiving a request from the first user to link to the second user; sending to the second user a notification of the request; and receiving a reciprocating request from the second user to link to the first user. 